1. Field of the Invention
The present invention relates to a thin film transistor array substrate and a display using the same, and more particularly, to a thin film transistor array substrate having a testing pad for testing electrical characteristics of a thin film transistor, a display using the same, and a method of fabricating the same.
2. Discussion of Related Art
In a display, such as an active matrix light emitting display, a thin film transistor (TFT) is provided in a pixel and used for switch-controlling a pixel electrode. The TFT may be made of a high or a low temperature poly silicon or amorphous silicon and is formed on an insulating substrate, such as a glass substrate or quartz substrate.
A substrate, referred to as a TFT substrate, includes a circuit having the TFT that is provided in an image displaying region and/or a region neighboring the image displaying region.
Electrical characteristics of the TFT are tested before forming the pixel electrode on each pixel of the TFT substrate. The testing process for the TFT substrate is performed using an array tester for testing operations of an adjacent circuit. The array tester is classified as an e-beam type, a capacitor coupling type, or a direct contact type.
For example, in the direct contact type array tester, the corresponding TFT is electrically tested by transmitting an electrical signal to the pad 6 through a testing probe directly contacting a pad 6 and then reading the electric signal again through the testing probe. The pad 6 is formed on one side of the TFT substrate 10 and connected to the TFT (not shown) through a signal line 4, as shown in FIG. 1.
The direct contact type array tester is applicable for a high-resolution display having small-sized pixels.
However, in the direct contact type array tester, since the testing probe directly contacts the pad 6 of the TFT substrate, scratches may be formed on the pad 6. Such scratching may cause defects while the display is fabricated. That is, the scratch formed on the pad 6 due to the direct contact type array tester causes defects, such as pad 6 corrosion, circuit damage, or the like.